Sampling mantle rocks with the Oman Drilling Project

This blog post has been written by Elliot Carter, NERC funded PhD student in the Univeristy of Manchester SEES Isotope Group

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Back in February I applied to join the Oman Drilling Project, a massive international co-operative scientific endeavour to learn more about what occurs deep beneath seabed in oceanic crust and mantle. To my delight I was accepted and now find myself living aboard a huge drilling ship for a month.
The core of the project is a two year program to drill hundreds of metres below the surface of the desert in Oman.  While it might seem counter-intuitive to be looking for seafloor in a desert, the mountains of Oman are famous among geologists for having the one of the largest, best and most studied areas of observable oceanic crust and mantle anywhere in the world. Such geological formations are known as ophiolites and are formed when sections of the oceanic crust get thrust up on top of the continents during episodes of continental collision.
Drilling the ophiolite allows us to recover parts of these rocks which simply weather away under the harsh desert sun. Once these cores have been drilled (a long story in itself) they need to be studied and described by a team of scientists. That is where my involvement comes in.

 

Chikyu

The Chikyu in all its glory (note van for scale). Photo: Elliot Carter

Again somewhat counter-intuitively, the cores have been shipped halfway round the world to Japan where they are being intensively studied aboard an extraordinary boat called the RV Chikyu. Measuring 250 m in length and weighing just shy of 57,000 tons (!) the Chikyu is purpose-built to drill the ocean-floor in great depths of water. It was specifically designed in mind of the longstanding goal of drilling to the Earth’s mantle. Scientists have been attempting to do so since the mid-1950s but the extreme requirements of drilling up to 10,000 m beneath the waves have thwarted all attempts so far. Because of its design the Chikyu is uniquely well-equipped to handle the cores from Oman, with an array of facilities and analytical instruments which would embarrass many prestigious universities.  Over the course of two months, just over 60 scientists from 14 countries will live on the Chikyu, working round the clock to describe, analyse and catalogue 1500 m (or around a mile) of cores from Oman. The first leg finished on 15 August while leg 2, which I am a part of, is just beginning.

Attire

Trying on my snazzy new jumpsuit

Life on a ship, especially one as large as the Chikyu is quite a surreal experience. In order to get everything done within the month we must work in shifts, with half the scientists working noon till midnight while the rest take over from midnight to noon. As a result, there are four mealtimes a day in the mess hall. Those working late shifts often end up having some strange meals at strange times, such as noodles and tempura prawns at midnight for breakfast. A common question late at night is “Good morning? Good night?”. Much of the three-floor laboratory area lacks windows and, with the strange shift hours, it can be quite disorientating. For fresh air and sunlight we are free to walk up to the helipad on the top deck of the ship (from where I’m writing this). When time permits, it is well worth the effort of climbing the nine flights of stairs from the mess hall to marvel at the activity of the port and, on clear days, catch a glimpse of mount Fuji.

Despite all these unusual and fun new experiences perhaps the best the best thing about being part of this project is the sense of energy and collective purpose of working together with 30 other scientists utterly focussed on different aspect of a broader goal. In this post I haven’t given much space to how exciting the actual science being done aboard is. The project will deliver insights into fundamental questions about the deep Earth, including how ocean crust is formed, how huge volumes of volatile elements cross tectonic plates at subduction zones and how carbonation of peridotite (a mantle rock) might offer some mitigation against the man-made disaster that is global warming. In many ways, the project is also a first step in preparing the Chikyu, its technical staff and its facilities for the particular challenges ahead in attempting to drill to the mantle. I hope to cover all this, as well as more about the joys, trials and peculiarities of shipboard life, in future posts.

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About Katherine Joy

Hello! I am Katherine Joy. I am part of the University of Manchester Isotope Geochemistry and Cosmochemistry group. More details about my research interests can be found at http://www.seaes.manchester.ac.uk/people/staff/profile/?ea=katherine.joy
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One Response to Sampling mantle rocks with the Oman Drilling Project

  1. Pingback: Sampling mantle rocks with the Oman Drilling Project – Part 2 | Earth & Solar System

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